ceph: trim unused inodes before reconnecting to recovering MDS

So the recovering MDS does not need to fetch these ununsed inodes during
cache rejoin. This may reduce MDS recovery time.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index bad07c09f91ead03419fe8e25fb1df18b4ac439e..f751fea416e5721e5bd39bcf9d21efde110901f0 100644 (file)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2695,16 +2695,6 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc,
        session->s_state = CEPH_MDS_SESSION_RECONNECTING;
        session->s_seq = 0;
 
-       ceph_con_close(&session->s_con);
-       ceph_con_open(&session->s_con,
-                     CEPH_ENTITY_TYPE_MDS, mds,
-                     ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
-
-       /* replay unsafe requests */
-       replay_unsafe_requests(mdsc, session);
-
-       down_read(&mdsc->snap_rwsem);
-
        dout("session %p state %s\n", session,
             session_state_name(session->s_state));
 
@@ -2723,6 +2713,19 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc,
        discard_cap_releases(mdsc, session);
        spin_unlock(&session->s_cap_lock);
 
+       /* trim unused caps to reduce MDS's cache rejoin time */
+       shrink_dcache_parent(mdsc->fsc->sb->s_root);
+
+       ceph_con_close(&session->s_con);
+       ceph_con_open(&session->s_con,
+                     CEPH_ENTITY_TYPE_MDS, mds,
+                     ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
+
+       /* replay unsafe requests */
+       replay_unsafe_requests(mdsc, session);
+
+       down_read(&mdsc->snap_rwsem);
+
        /* traverse this session's caps */
        s_nr_caps = session->s_nr_caps;
        err = ceph_pagelist_encode_32(pagelist, s_nr_caps);